Heat the butter and oil in a dutch oven over medium-high heat. Rub the roast all over with salt and pepper. Brown the beef on all sides in the hot butter and oil. It should take about 10 minutes. Pour the cognac into the pan, warm it, and flame with a match

Pour in the stock and 1/2 cup of the wine, cover the pan and simmer slowly over low heat for about 3 hours, adding more wine so that there's always about 1 cup liquid in the pan.

Remove from heat and let cool to room temperature. Remove the beef and shred into small pieces, following the natural grain of the meat. Return the shredded beef to the liquid in the pan. heat until warmed through - Serve as is, sprinkled with parsley on toast.